JPH0271869A - Applicator - Google Patents

Abstract

PURPOSE:To make an applicator lightweight and to make maintenance simple by utilizing ceramic which has specified linear thermal expansion coefficient and Vickers hardness and has been sintered at high temp. not lower than 1,000 deg.C as material constituting a coating equipment for applying coating liquid on a traveling web. CONSTITUTION:Ceramic which has been sintered at high temp. not lower than 1,000 deg.C and has <= 11 X 10<-6>/ deg.C linear thermal expansion coefficient at 25 - 500 deg.C and >= 700kg/mm<2> Vickers hardness is utilized as material constituting an applicator. The applicator applied with this material by which coating liquid is uniformly applied on a continuously traveling web is equipped with e.g. a multisliding hopper, etc., and an ancillary facility thereof. Both the change in distribution of slot width due to thermal strain and the change in distribution of coated amount in the width direction on the web are regulated to a range within respective measuring errors by the specified linear thermal expansion coefficient. Further wear resistance is made more superior than metal by the specified Vickers hardness. Furthermore the applicator is made lightweight and maintenance can be made simple.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a coating device that uniformly coats a fixed amount of coating liquid onto a continuously running nib. In particular, the present invention applies to a continuously running long flexible support (hereinafter referred to as a "web") in the production of recording materials such as photographic film and paper, photolithographic materials, pressure-sensitive recording paper, and heat-sensitive recording paper. The present invention relates to a coating device for improving the coating surface quality when applying a liquid coating composition (hereinafter referred to as "coating liquid") to a surface (hereinafter referred to as "coating liquid"), and more specifically relates to materials for manufacturing the coating device.

(Prior Art) As a conventional method and apparatus for coating a photographic light-sensitive material on a support, for example, a multi-slide hopper (Japanese Patent Publication No.
No. 8977), multilayer curtain coating method (Special Publication No. 1983)
-239, Japanese Patent Application Laid-Open No. 54-74761), etc.

Furthermore, Japanese Patent Application Laid-Open No. 62-227464 is disclosed as a coating device material for a photographic light-sensitive material.

Furthermore, Japanese Patent Application Laid-Open No. 62-95170 is disclosed as relating to a material for a magnetic material applicator.

As is clear from the above invention, it is a photographic light-sensitive material.

For magnetic recording materials and information recording materials, in order to maintain product uniformity and manufacturing stability, each 41m coating device must be manufactured with high precision, and must not be affected by corrosion due to the coating liquid. is strongly required.

[Problem to be solved by the invention]

However, conventional coating devices have the following problems: (1) Regardless of the type of hopper (liquid pourer) that has been used, the number of blocks has increased due to multilayer coating, and the weight of the main body has increased. Of course, if the coating is multi-layered, the accuracy of the application position of the pumper will be increased (the moving table on which it is set is designed to have a large weight to withstand this weight, and therefore the drive device also requires a very large amount of horsepower). .

(2) Furthermore, for periodic maintenance (especially cleaning), the hopper is transported using trolleys, cranes, etc., but the strength and horsepower of all these equipment are proportional to the total weight of the hopper equipment, making them large. Ancillary equipment costs are high.

(3) The blocks of various hoppers are disassembled and reassembled during periodic cleaning, but even a single hopper weighs a lot and requires the use of a crane for transportation, but high accuracy is maintained. In order to prevent injury to the main body, the disassembling and assembling workers not only need to be skilled but also take great care, which requires a large number of man-hours.

(4) Due to thermal deformation of the hopper material, there are restrictions on the conditions of use of the hopper.In other words, one of the effects of thermal deformation is that the distribution of the clearance in the hopper slot section increases, which increases the distribution of coating amount in the width direction of the support. This not only causes differences in product performance at each slit position in the width direction, but also causes meandering and wrinkles during web transport immediately after coating, especially in the case of information recording paper, and causes unevenness during winding. You may not be able to wind it properly (wrong winding).

For this reason, in order to minimize this effect, and as a countermeasure, devices have been installed to control coating liquid temperature and heat retention, and handling equipment such as pass rolls and expander rolls has been increased to prevent meandering and wrinkles.

Furthermore, the average coating amount has been increased to ensure basic product performance even at the lowest point in the coating amount distribution.

Another effect of thermal deformation is that it deteriorates coating stability in the case of slide hoppers and extrusion hoppers.

In coating using a slide hopper or an extrusion hopper, the gap between the hopper tip and the backup roll is an important factor for stabilizing high-speed coating, but due to thermal distortion of the hopper, this gap in the width direction In order to deal with the problem of sag due to large distribution and poor stability of high-speed coating, we have further improved the coating properties of the coating liquid so that it can withstand continuous manufacturing even if there is a large distribution in the width direction in this gap. Various surfactants and the like are added more than necessary.

(5) Not only the coating of photographic light-sensitive materials (even in the coating of information recording materials and magnetic recording materials, some of the coating liquids and cleaning liquids have a pH of 5 or lower or 10 or higher,
Corrosion of the hopper material becomes a problem.

(Japanese Patent Application Laid-Open No. 62-227464) When IiIM occurs, it causes streaks on the paint film, the cleaning performance of corroded areas deteriorates, and the residual liquid mixes when switching applications, resulting in performance problems for other products. There are also concerns about the impact on

For this reason, the hopper is periodically disassembled and cleaned, and the presence or absence of corrosion is checked. If corrosion is found, the block is immediately repolished or remanufactured.

(6) In particular, many coating fluids for magnetic recording materials are highly abrasive, and the tip of the hopper can become frosted over a certain period of use.
It may cause streaks or make stable application impossible.

For this reason, maintenance such as frequently replacing and regrinding the hopper tip is required.

In view of the above-mentioned problems, the purpose of the present invention is to (1) reduce the weight of the hopper and auxiliary equipment to reduce equipment costs; and (2) improve the precision of the hopper (minimize heat effects) to ensure stable coating over a wide range of conditions. This eliminates the need to add more than necessary surfactants to the coating solution. In addition, uniform coating is performed across the width of the support over a wide range of conditions (temperature conditions), creating products with more uniform performance. This also makes the conveyance of the web after coating more stable, improves the product bulk winding condition, and stabilizes the degree of slitting to various product sizes, increasing the efficiency of the manufacturing to processing process and increasing productivity. (3) Improve the durability (chemical resistance, wear resistance) of the phone bar and reduce maintenance costs.

The object of the present invention is to provide a coating device that can do the above.

[Means for Solving the Problems] The above-mentioned object of the present invention is to provide a coating device that uniformly coats a certain amount of a coating liquid onto a continuously running web, using a high-temperature coating of 1000° C. or higher as a material for the coating device. Ceramink obtained by sintering in
This is achieved by a coating device characterized by using a coating material with a coating capacity of 00 kg/tra'' or more.

The ceramic in the present invention refers to alumina (A l 2
0ri, silcore (ZrO), silicon carbide (Sic),
Each single raw material of silicon nitride (s13Ng) with a purity of 80X or higher.

It refers to a ceramic material obtained by sintering a mixed material containing other elements such as Si, Al, Ti, C, N + O + as main components at a high temperature of 1000° C. or higher.

Specifically, the coating device in the present invention includes, for example, a multi-slide hopper (Fig. 1), a multi-extrusion hopper (Fig. 2), and a curtain hopper (Fig. 3).
, multi-extrusion curtain hopper (Fig. 4), multi-extrusion slide type curtain hopper (Fig. 5), 5 slide type curtain hopper (Fig. 6), etc., liquid injection device (hopper) (of course - employment hopper) It goes without saying that this refers to the coating equipment, including the hopper installation stand, moving equipment, and other accessory equipment required to operate it.

In the present invention, by sintering the ceramic material at a high temperature of 1000° C. or higher, its compactness increases, and when a hopper is manufactured, sufficient water retention can be achieved. Water retention means that the coating liquid (water-based or solvent-based) or warm water supplied into the hopper does not seep into the material even when a pressure of ~5 kg/c+a is applied. The sintering temperature varies depending on the purity of the material, but when the purity is 80% or more, the sintering temperature is 10%.
00℃ or higher.

In the present invention, if a material with a linear thermal expansion coefficient of 11 X I O-'/''C or less at 25 to 500°C is used, changes in the slot width distribution due to thermal distortion of the hombur material and furthermore, the amount of coating in the width direction on the web can be reduced. All changes in distribution were within the respective measurement error ranges, and it was found that this was significantly improved compared to stainless steel material.

By using a material with a Vickers hardness of 700 kg/1 m'' or higher, the present invention not only has higher wear resistance than metal, but also has virtually no effect of distortion caused by bolt tightening on the assembly accuracy of each block that makes up the hopper. I won't receive it.

Regarding assembly precision, the structure of the honbar consists of several blocks depending on the number of layers, and each block is assembled with bolts with their flat surfaces aligned with each other. In addition, the coating device as a whole includes several accessories fixed to the hopper body with bolts.

The hopper and its accessories are bolted together with a large torque to prevent the coating liquid and warm water supplied to the hopper from leaking from the joint, and to maintain and reproduce the accuracy of the combination.

If the hopper is made of the above ceramic material, the processed surface will be different from that of conventional stainless steel material (surface irregularities, undulations), so it is necessary to assemble them and obtain the above functions than in the case of stainless steel material. The bolts must be tightened with even stronger torque. At this time, if the Vickers hardness is not at least 700 kg/mm, deformation or chipping of the material will occur.

Furthermore, by setting the purity of the ceramic material to 80% or more, the corrosion resistance level for each coating liquid of photographic photosensitive materials and information recording materials 1 and magnetic recording materials can be significantly improved compared to stainless steel materials without any significant difference. understood.

The horn and bar of each applicator are the blocks that form it (
1, 2, 3, 4, 5, 6) by cutting and polishing the blocks and the liquid supply pipes (7, 8, 9, 10, 11) between the blocks.
, cavity (%>12.13, 14, 15.16
), forming slots (17, 1B, 19.20.21).

Therefore, even if the finishing accuracy is the same, the precision of the hopper that uniformly distributes the coating liquid on the support depends on the coefficient of linear thermal expansion of the material forming the hopper due to temperature changes, and on long-term use. The hardness of the material is influenced by the hardness of the material in terms of wear.

The present invention is a ceramic obtained by sintering at a high temperature of 1000°C or higher, and has a coefficient of linear thermal expansion of 25 to soo compared to the conventional one of about 172.
'cc 711 x 10-'/'C or less, the hardness is about 5 times that of metal, and the load is 500g.
700 kg/m" or more.

The present invention is characterized by using a ceramic having such characteristics.

[Function] By using ceramic having the above-mentioned conditions as the material for the coating device of the present invention, the specific gravity becomes 172 or less compared to conventional stainless steel, making it possible to significantly reduce the weight of the device. The coefficient of linear thermal expansion is 1/2 of that of conventional products, so there is little deformation due to heat, so a wide range of coating liquid temperatures can be selected, and the corrosion resistance against acids and alkalis is overwhelmingly strong, so it can withstand a wide range of coating liquid types and long-term use. It is also much harder than metals, has excellent wear resistance, and can be used for long periods of time.

[Example] Example-1 A multi-threaded hopper with a block diameter of 1500 mm and a thickness of approximately 50 strokes was manufactured using the materials shown in Table 1, using a hopper with 3 layers and 4 blocks as shown in Figure 1, and a sloft. 17#1
am, sloft 18', 0.7 mm, material No. 61, as represented by slot 19, was in very good condition.

Table 4 Table 5 shows the speed limit at which it is impossible to uniformly coat the substrate by gradually increasing the coating speed.

As shown in Table 5, it is not only a revolutionary change to the coating device itself, but also a great effect as a coating device for photography.

Example-2 A single-layer bronc as shown in Figure 3 using the materials and sintering conditions shown in Table 6, an extrusion chamber with a width of 1000 m + a, J'; f of approximately 50 mm, adjusted to a width of 1 mm, before use 1 Also, the variation in the throat gap during coating and the coating amount distribution in the width direction of the web should be applied as shown in Section 7! ! ! The specific ceramic of the present invention as a lid material is selected not only from the viewpoint of corrosion resistance but also from the linear thermal expansion coefficient and hardness. ) Significant cost savings due to lighter coating equipment production]
・It is now possible to go down. Furthermore, by reducing the weight, it is possible to reduce the power capacity and make the entire equipment more compact.

(2) Reduced product costs Even if the additive chemicals that determine the applicability to the coating solution are reduced, uniform and stable coating is possible, and uniform coating stabilizes the manufacturing (coating) to processing process. was realized.

(3) Simplified equipment maintenance Since the material is more resistant to chemicals than metal, its durability is increased, maintenance can be simplified, and its weight is reduced, making it easier to handle.

(4) Improving product quality and stabilizing production. Uniform coating amount in the width direction of the support by increasing the precision of the hopper.
Also, by stabilizing the liquid bridge between the support and the hopper in the slide and extrusion hopper, quality improvement and production stability were promoted.

[Brief explanation of the drawing]

Figure 1 is a multi-slide hopper, Figure 2 is a multi-extrusion hopper, Figure 3 is a curtain hopper,
FIG. 4 shows a multi-extrusion curtain hopper, FIG. 5 shows a multi-extrusion slide type curtain hopper, and FIG. 6 shows a side sectional view of a slide type curtain hopper. 1.2.3, 4, 5.6 ... Flock 7.8, 9
．． 10.11 ...Liquid supply pipe 12. +3.14.
15.16 ... Cavity 17, 18.19, 2
0.21...Slot 22...Support f: Cutting diagram

Claims (1)

[Claims] In a coating device that uniformly coats a certain amount of coating liquid onto a continuously running web, as a material of the coating device, 1
Ceramic obtained by sintering at a high temperature of 000°C or higher and has a linear thermal expansion coefficient of 11 x 10^-^6/ at 25 to 500°C.
℃ or less and a Vickers hardness of 700 kg/mm^2 or more.